"It's a growing trend, especially in Asia, and a lot of these phones are favoured by women, women who don't have to worry putting it into their pockets, they carry it in their purse," said Ken Hong, communications director at LG.

More than 120 million tablets were sold worldwide in 2012, up 50 percent from the previous year, and shipments of smartphones are predicted to hit one billion this year according to global consultants Deloitte.

But the size of tablets is shrinking.

The Samsung Galaxy Note 8, released just ahead of the congress, trimmed its screen to eight inches to compete with Apple's new iPad mini.

Taiwan's Asus has managed to marry the two devices.

Asus showed off the Padfone Infinity, a five-inch, high-definition screen smartphone that can harness the latest superfast fourth-generation wireless network and which slots into 10.1-inch tablet.

The smartphones of 2013 have to be fast, too, however, as the 4G network, also known as Long Term Evolution, or LTE, expands worldwide.

China's Huawei unveiled a new mobile at the show, the Ascend P2, which it claims is the fastest in the world.

Sharp-cornered and thinner than a pencil at 8.4 mm, the company said it can achieve speeds of 150 Mbps, fast enough to download a two-hour high-definition movie in less than five minutes.

The mobile, which has a more modest 4.7-inch, high definition screen, is powered by a 1.5 GHz quad-core processor and is able to use LTE networks.

Huawei held 5.3 percent of the market in the fourth quarter of 2012.

That is still well behind Samsung and Apple which held more than 50 percent of the sales combined 29.0 percent for Samsung and 22.1 percent for Apple.

If you can't be the biggest, smallest or fastest, there is another way to the hearts of mobile phone consumers.

Finnish manufacturer Nokia, once the leader of the mobile phone world, tried to lure shoppers with lower prices.

Nokia released two Windows Phone-operated smartphones the Lumia 520 and 720 to be offered with pre-tax price tags of 139 euros ($189) and 249 euros respectively.

But Nokia also offered the Nokia 105, the kind of mobile handset people use mostly for making telephone calls, for just 15 euros.